A single 802.11g access point has been configured and installed in the center of a square office. A few wireless users are experiencing slow performance and drops while most users are operating at peak efficiency. What are three likely causes of this problem (Choose three.)（）。
- Amismatched TKIP encryption
- Bnull SSID
- Ccordless phones
- Dmismatched SSID
- Emetal file cabinets
- Fantenna type or directio